Is Periodontitis a Risk Factor for Lung Cancer? A Meta-Analysis and Detailed Review of Mechanisms of Association.

Background: Numerous studies have explored the correlation of periodontal disease (PD) with the risk of lung cancers, but the findings were inconsistent. Therefore, we did a meta-analysis to ascertain the correlation of PD with the risk of incident lung cancer. Methods: The authors searched relevant studies in databases (PubMed, Web of Science, Scopus, Embase, and MEDLINE) till November 2020. We registered the study at the International database of Prospectively Registered Systemic Reviews under the CRD42020198119. The summary relative risk (RR) along with a 95% confidence interval (CI) was calculated using fixed-effects models. Results: Twelve studies were included in the qualitative synthesis. The pooled analysis revealed that PD was significantly associated with an increased risk of lung cancer (RR 1.71; 95%CI 1.61-1.81; P < 0.01). Subgroup analysis was performed based on gender distribution, geographic location, and type of studies. Conclusion: From this current evidence, PD is a potential risk factor for the development of lung cancer. The risk for incidence of lung cancer is surged twice in the patients with PD, even though age and smoking are controlled in the studies.

Cyclic Fatigue Resistance and Surface Roughness of Rotary NiTi Instruments after Simulated Clinical Use in Curved Root Canals - An Atomic Force Microscopy Study

Abstract Objective: To examine the cyclic fatigue resistance and surface topography of TruNatomy and ProTaper Gold nickel-titanium rotary files and evaluate the presence of alterations to surface topography following instrumentation in simulated curved canals. Material and Methods: Twenty-four nickel-titanium instruments, twelve each of TN and PTG file systems, were evaluated for cyclic fatigue resistance. The rotary files were rotated in a simulated root canal with standardized diameter, angle of curvature, and radius of curvature in a custom-made cyclic fatigue testing device until the instrument fracture occurred. The time to fracture for each instrument was recorded with a stopwatch; in seconds in each group. Fractured instruments were subjected to atomic force microscopy analysis measuring the average roughness and the root mean square values to investigate surface features of endodontic files. Mean values and standard deviation were calculated. Data were analyzed using the Mann-Whitney U test. Results: Time to fracture was marginally higher in PTG instruments than in the TN file systems. PTG files exhibited higher surface roughness when compared with TN files (p<0.05). Conclusion: TN file system had a higher cyclic fatigue resistance than PTG. Cyclic fatigue causing file breakage did affect the surface topography of the files. PTG files showed a higher surface porosity value than the TN files (AU).

Microleakage Evaluation of an Alkasite Restorative Material: An In Vitro Dye Penetration Study.

AIM: The aim of the present in vitro study was to comparatively evaluate the microleakage in three different esthetic restorative materials in class I cavities using the dye penetration technique. MATERIALS AND METHODS: Class I cavities were prepared on 24 human maxillary premolar teeth. The teeth were randomly divided into four groups of six samples each. Group I: Cention-N without adhesive (Ivoclar Vivadent, India), group II: Cention with adhesive (Ivoclar Vivadent, India), group III: type IX glass ionomer cement (Fuji), group IV: posterior composite (3M ESPE). The specimens were polished, subjected to thermocycling, and suspended in methylene blue dye for 24 hours. The teeth were sectioned longitudinally and the extent of microleakage was evaluated using the stereomicroscope. RESULTS: The results were subjected to statistical analysis using the Pearson's Chi-square test and the interobserver variability was assessed by the Kappa test for interobserver variability. The analysis showed statistically significant results among the groups. Although, Cention N with adhesive showed the least microleakage followed by Cention N without adhesive. CONCLUSION: All the materials tested were unable to completely eliminate microleakage in class I cavities. However, the newer alkasite material Cention N proved to have the least microleakage among all groups. CLINICAL SIGNIFICANCE: According to the present study, Cention N, a newer alkasite restorative material, demonstrated promising results with the least microleakage in comparison with posterior resin composites and glass ionomer cements. How to cite this article: Kini A, Shetty S, Bhat R, et al. Microleakage Evaluation of an Alkasite Restorative Material: An In Vitro Dye Penetration Study. J Contemp Dent Pract 2019;20(11):1315-1318.